Structure formation of entanglement entropy in a system of two superconducting qubits coupled with an LC-resonator  

作　　者：葛国勤 覃翠 尹淼 黄勇华 

机构地区：[1]School of Physics,Huazhong University of Science and Technology

出　　处：《Chinese Physics B》2011年第8期39-46,共8页中国物理B（英文版）

基　　金：Project supported by the China "State 973 Project" (Grant No.2006CB921606);the Natural Science Foundation of HubeiProvince of China;the Innovation Fund of Huazhong University of Science and Technology (2010)

摘　　要：This paper investigates theoretically the evolutions of the entanglement entropy of a system of two coupled-charge- qubits interacting with an LC-resonator. It is found that when the initial states of the two qubits are prepared in a given superposition excited state, the evolution of the von Neumann entropy of the system depends significantly on the coupling strength between the two Josephson charge qubits. With the variation of the coupling strength, the evolution of the entanglement entropy of the system forms some structures, especially the periodically bistable properties, which are the first discovered for such a system to our knowledge. It is found that the relative entropy entanglement of the system is also sensitive to the variation of the coupling strength between the two charge qubits, some novel ＇collective oscillations＇ of the relative entropy are found for the system.This paper investigates theoretically the evolutions of the entanglement entropy of a system of two coupled-charge- qubits interacting with an LC-resonator. It is found that when the initial states of the two qubits are prepared in a given superposition excited state, the evolution of the von Neumann entropy of the system depends significantly on the coupling strength between the two Josephson charge qubits. With the variation of the coupling strength, the evolution of the entanglement entropy of the system forms some structures, especially the periodically bistable properties, which are the first discovered for such a system to our knowledge. It is found that the relative entropy entanglement of the system is also sensitive to the variation of the coupling strength between the two charge qubits, some novel ＇collective oscillations＇ of the relative entropy are found for the system.

关 键 词：superconducting quantum circuits evolutions of entanglement entropy structure forma-tion 

分 类 号：O413.1[理学—理论物理]